Thank you for all of your suggestions! Having both of these names to compare made a definitive conclusion possible.
Janet, I am convinced that it is strigosus. The roots on mine have no "nuts".
http://ir.library.oregonstate....
I dug up two specimens (at different stages of maturity) and mine definitely do not have them. Plus, the spikelets are scattered-looking, rather than in rows of four as in esculentas. The scale pattern matches as well.
As an aside - I almost wish it was esculentas...those tubers are edible and nutritious.
I find learning about *different* food sources fascinating!
Thanks, again. I thought I'd never get this one figured out!
